This invention relates to electrical power wires and, more particularly to, devices for metering electric power wires.
It should be noted in passing that in the metering of power and energy, the two terms are often used interchangeably. In strict terms, this is erroneous. The familiar “power” meter on a customer's premises actually measures the amount of energy consumed over a period of time. A customer is changed by the energy consumed. Power is the rate at which energy is being delivered to, and consumed by, the customer.
Current metering technology is bulky and the required wiring of the current transformers, which monitor the current carried by the wires to the customers, is confusing. A particular problem is the identification of all the load-carrying wires with the current transformer signal leads. Up to now, an electrician must identify the individual leads among a thicket of similar looking wires. This makes installation of power metering a complex and error-prone process. Such problems discourage the retrofitting of metering to sites where metering to individual consumers is not done but highly desirable. For example, many apartment buildings have only a single metering device for the entire building, though individual billing is highly desirable due to issues of environmental responsibility, legislative constraints and pressure to lower costs. However, the electrical wiring of such buildings is not conducive to retrofitting metering. Extensive rewiring is required with conventional metering, which makes the task in a finished building nearly impossible or extremely difficult.
To avoid or ameliorate the problems of conventional metering, the present invention provides for an electrical metering device at the power distribution cabinet. Power distribution cabinets are located near the end of electricity distribution networks to supply customers, such as homes and businesses, with electricity. Electrical wires from the power distribution cabinets provide the link from the electricity distribution networks to the customer's premises. The present invention allows for the monitoring the amount of energy supplied to each customer by an economical arrangement which is simple to install, easy to calibrate and is accurate. Rearrangements to supply power to customers are easily accommodated.
The present invention provides for such an improvement.